ARR cars started appearing stateside after the rail barge service started in the mid 60's.  You'll see shots from all over the US.  Gons were frequent, and the ex troop cars converted to boxcars.  Flats and hoppers too.  Thus you won't find ARR rosters in ORER's before then.

The Sunshine ARR gon model is nice, ARR's had a different end that he did nicely.  FYI, the kit decals were the wrong color (white but should be yellow).  I did a replacement decal for Martin but not sure how many ARR models he sold.  These 40', and the ex DRGW mill gons, are still in MOW service here.

Curt Fortenberry